1. Field of the Invention
The present invention relates to operational amplifier technology and more particularly to an improved operational amplifier with improved gain and bandwidth.
2. Description of Previous Art
As very large scale integration (VLSI) circuits with more and more functions and higher operating speeds are being developed for integrated system applications, the demand for higher performance operational amplifiers for integrated system applications steadily grows. Functions that required three or four chips in the past are now being performed by a single VLSI circuit. The higher operating speeds provide faster circuits and quicker responses from electronic devices. Currently, an amplifier design well suited for integrated system applications is a folded cascode complimentary metal oxide silicon (CMOS) operational amplifier (op amp) design. The folded cascode CMOS op amp can be implemented readily on a VLSI circuit wafer and incorporated with other VLSI circuits. Increasing the gain of op amps permits signals within the VLSI circuits to operate at lower levels which reduces noise and power consumption of VLSI circuits. Increasing the bandwidth capabilities permit the op amp to operate at higher frequencies.
It is desirable to provide an op amp design well suited for VLSI circuits, and a method of operating the same which provide increased gain and bandwidth without suffering from increased size and power dissipation penalties of existing designs.